This replacement lightbulb is designed to only fit in 13W OttLite Battery Task Lamps. Please ensure you have the right lamp and bulb before purchase. Note that this bulb has 4 pins. OttLite's Type F bulbs show colors true to life and produce clearer details, all while reducing eye strain. This bulb will provide you with low heat and low glare illumination for years to come.Details:Replacement bulb type F4 pinsFor use only as a replacement bulb for OttLite 13W Battery Task LampsTrue colors, clear details and reduced eyestrainLow-heat, low-glare illuminationEnergy efficientRated to last up to 10,000 hours